Sodium trapping agent as well as preparation method, application and regeneration method thereof

Abstract

The invention provides a sodium trapping agent, a preparation method, application of the sodium trapping agent and a regeneration method of the sodium trapping agent. The sodium trapping agent comprises aluminum oxide, a molecular sieve and inorganic acid. The molecular sieve is crystallized on aluminum oxide. The preparation method of the sodium trapping agent comprises the following steps: mixing alumina powder or formed alumina with a precursor of a molecular sieve, carrying out hydrothermal treatment, washing, drying and roasting, and introducing inorganic acid through an impregnation method. The sodium trapping agent is applied to oil product sodium removal, and after saturation, the sodium trapping agent can be regenerated through simple operation of washing in an aqueous solution containing ammonium salt and then introducing inorganic acid. According to the sodium trapping agent, aluminum oxide with the large specific surface area serves as a substrate, the molecular sieve is crystallized on the aluminum oxide, the dispersity of the molecular sieve on the surface of the aluminum oxide can be effectively improved, and more adsorption sites are provided for sodium; and the inorganic acid can effectively improve the acid content on the surface of the sodium trapping agent and improve the adsorption trapping amount of sodium.

Description

Technical Field

[0001] The present invention relates to the technical field of oil hydrogenation, and specifically relates to a sodium capturer for oil products, a preparation method thereof, and an application and regeneration method of the sodium capturer. Background Art

[0002] In recent years, with the increasing heavy and inferior quality of petroleum resources, as well as the extensive use of a large number of oilfield chemicals in the oil production and gathering and transportation processes, the proportion of pollutants in the crude oil processed by refineries has increased. Among them, the negative impact of metal pollutants on the hydrogenation catalytic process is becoming more and more serious. In particular, sodium pollutants will continuously deposit on the catalyst during the hydrogenation reaction process, causing catalyst poisoning by blocking pores, covering active sites, etc., and this process is generally irreversible.

[0003] CN201910466079.X discloses a method for removing sodium salts from hydrocarbon oils, including: mixing a hydrocarbon raw material oil with a quaternary phosphonium salt sodium removal aid, a demulsifier and water in a mixer, and entering an electrostatic desalting device for desalting treatment to obtain a hydrocarbon oil with a significantly reduced sodium content. The quaternary phosphonium salt is a compound with the general formula [R1P+(R2) 3 n X n- , where R1 is an alkyl or alkoxy group with 8 - 22 carbon atoms; R2 is an alkyl or hydroxyalkyl group with 1 - 4 carbon atoms, a phenyl group or a benzyl group; n is an integer from 1 to 3, and X is an anion group. The method of this invention can effectively solve the problem of metal sodium pollution of the catalyst in the oil refining catalytic cracking unit caused by oilfield chemicals, and greatly reduce the risk of sodium poisoning of the catalytic cracking catalyst.

[0004] CN202010565958.0 discloses a sodium ion adsorbent, which contains the following components: 10 - 30 parts by mass of Li 3 Fe 2 (PO 4 ) 3 or Li 3 V 2 (PO 4 ) 3 , 10 - 30 parts by mass of LiSn 2 (PO 4 ) 3 or LiMn 2 (PO 4 ) 3 and 40 - 80 parts by mass of LiTi 2 (PO 4 ) 3 ​; It also provides a method for preparing the sodium ion adsorbent of the present invention. The sodium ion adsorbent of this invention is used for removing sodium ions under gas-solid phase conditions, preferably under gas-solid phase conditions of 300 - 600 °C, and more preferably in the catalyst bed of a gas-solid phase reactor at 300 - 600 °C. The adsorbent of this invention has high thermal stability and high adsorption selectivity under high-temperature gas-solid phase conditions.

[0005] Currently, the feedstock oil of some hydrogenation units contains a small amount of sodium (sodium content ≤ 1 ppm). The small amount of sodium in the oil will cause sodium poisoning of the hydrogenation catalyst, resulting in a sharp decline in catalyst activity. The sodium removal method of the above-mentioned invention patent mainly uses an electro-desalting device for sodium removal. If an electro-desalting device is set before the oil hydrogenation unit, the production cost will be greatly increased. Moreover, most of the existing sodium adsorbent components contain metal elements such as lithium, vanadium, iron, tin, and titanium. When filled above the oil hydrogenation catalyst, it may cause metal impurity poisoning and inactivation of the hydrogenation catalyst. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the present invention provides a sodium scavenger, which improves the surface acid content of the catalyst by specific means, thereby improving the sodium capacity of the adsorbent, and can especially effectively remove sodium in the oil, playing a role in protecting the main catalyst.

[0007] The technical object of the first aspect of the present invention is to provide a sodium scavenger, which includes alumina, molecular sieve, and inorganic acid. The inorganic acid is selected from at least one of phosphoric acid, nitric acid, sulfuric acid, and hydrochloric acid; the molecular sieve is crystallized on the alumina.

[0008] Further, based on the total weight of the sodium scavenger, the weight percentage of alumina is 50 - 95%, the weight percentage of the molecular sieve is 3 - 30 wt%, and the weight percentage of the inorganic acid is 4 - 20%. As a further preference, the weight percentage of alumina is 60 - 93%, and more preferably 70 - 91%; the weight percentage of the molecular sieve is 4 - 20 wt%, and more preferably 8 - 15%; the weight percentage of the inorganic acid is preferably 4 - 15%.

[0009] Further, the total acid amount of the sodium scavenger is 0.3 - 1.1 mmol / g.

[0010] Further, the molecular sieve is selected from at least one of Y-type molecular sieve, β-type molecular sieve, and ZSM-5 molecular sieve.

[0011] The technical object of the second aspect of the present invention is to provide a preparation method of a sodium scavenger, which includes the following steps:

[0012] (1) Mix alumina powder or shaped alumina with the precursor of molecular sieve, conduct hydrothermal treatment, and after washing, drying and calcination, obtain the precursor of sodium trap agent;

[0013] (2) Introduce inorganic acid into the precursor of sodium trap agent, and then conduct drying to obtain the sodium trap agent.

[0014] The method adopted in the present invention is to introduce molecular sieve by in-situ reaction of the molecular sieve precursor on alumina. The precursor raw material crystallizes on alumina to obtain molecular sieve, rather than the direct mixing method, which increases the dispersion degree of the molecular sieve.

[0015] Further, when the raw material adopted is alumina powder, after introducing the molecular sieve, it also includes steps of mixing it with peptizing agent, extrusion aid and water, extruding and forming, conducting drying and calcination, and then introducing inorganic acid. Among them, the extrusion aid is well-known to those skilled in the art. As a more specific implementation manner, the extrusion aid is selected from at least one of starch, polyethylene glycol and sesbania powder. Calculated based on alumina, the addition amount of the extrusion aid is 2-8 wt% of alumina, preferably 3-5 wt%. The peptizing agent is well-known to those skilled in the art. As a more specific implementation manner, the peptizing agent is selected from at least one of nitric acid, phosphoric acid and acetic acid. Calculated based on alumina, the addition amount of the peptizing agent is 1-8 wt% of alumina, preferably 2-5 wt%; the addition amount of water is 50-150 wt% of alumina, preferably 80-120 wt%.

[0016] Further, the specific surface area of the alumina powder is 300-500 m 2 / g, and the pore volume is 0.9-1.4 cm 3 / g. The above requirements are also followed when selecting alumina for the shaped alumina.

[0017] Further, the precursor of the molecular sieve in step (1) is a gel formed by mixing a silicon source and / or an aluminum source, a precipitating agent, a templating agent and water. Its preparation method is well-known to those skilled in the art, and molecular sieve is formed by precipitation method or sol-gel method. Among them, the silicon source is selected from one or more of sodium silicate, tetraethyl orthosilicate, silica sol and chromatography silica gel; the aluminum source is selected from one or more of sodium aluminate, aluminum hydroxide and pseudoboehmite; the precipitating agent is selected from at least one of sodium hydroxide, ammonia water and potassium hydroxide; the templating agent is selected from one or more of cetyltrimethylammonium bromide, ethylenediamine, n-butylamine, tetrapropylammonium bromide, ethanol, tetraethylammonium hydroxide, tetraethylammonium bromide, triethylamine, di-n-propylamine, diisopropylamine and methyl cellulose.

[0018] Further, the hydrothermal treatment conditions in step (1) are as follows: the temperature is 90 - 200 °C, preferably 130 - 200 °C, the pressure is 0.1 - 2.0 MPa, the pH is 7.5 - 9.0, and the time is 5 - 48 hours.

[0019] Further, the drying temperature in step (1) is 70 - 150 °C, and the drying time is 4 - 16 hours; the calcination temperature is 400 - 800 °C, and the calcination time is 2 - 5 hours.

[0020] Further, the method for introducing the inorganic acid in step (2) is the impregnation method, and specifically preferably the equal - volume impregnation or supersaturated impregnation method.

[0021] Further, the drying temperature in step (2) is 80 - 120 °C, and the drying time is 3 - 8 hours.

[0022] The technical object of the third aspect of the present invention is to provide the application of the sodium capturer described in the first aspect or the sodium capturer prepared by the method described in the second aspect in the desodium of oil products.

[0023] The fourth aspect of the present invention provides a method for desodium of oil products, which includes contacting and reacting the oil product with the sodium capturer described in the first aspect or the sodium capturer prepared by the method described in the second aspect.

[0024] Further, the reaction conditions for desodium of oil products are as follows: the reaction temperature is 200 - 400 °C, the hydrogen partial pressure is 2.0 - 10 Mpa, and the volume space velocity is 0.5 - 6.0 h -1 .

[0025] The sodium capturer described in the first aspect of the present invention or the sodium capturer prepared by the method described in the second aspect has a saturation value for sodium adsorption and will lose its activity after being used for a certain period of time. Therefore, the fifth aspect of the present invention provides a regeneration method for the sodium capturer described in the first aspect or the sodium capturer prepared by the method described in the second aspect, which includes the following steps:

[0026] (1) Washing the sodium capturer saturated with adsorption in an aqueous solution containing an ammonium salt, and obtaining a precursor of the regenerant after drying;

[0027] (2) Introducing an inorganic acid into the precursor of the regenerant in step (1), and obtaining the regenerant after drying.

[0028] Further, the ammonium salt described in step (1) is selected from one or more of ammonium nitrate, ammonium sulfate, and ammonium chloride; calculated by the mass of the ammonium salt, the concentration of the ammonium salt in the aqueous solution is 0.2 - 1.2 g / mL, and the washing time is 4 - 10 h.

[0029] Further, the drying conditions in step (1) are: the drying temperature is 90 - 150 °C, and the drying time is 3 - 8 h.

[0030] Further, the process of introducing inorganic acid in step (2) is the same as that described in the second aspect of the present invention, and will not be repeated here.

[0031] Compared with the prior art, the technical solution provided by the present invention has the following advantages:

[0032] (1) The sodium capturer of the present invention includes alumina and molecular sieve. With high specific surface area alumina as the substrate, the molecular sieve crystallizes on the alumina, which can effectively improve the dispersion degree of the molecular sieve on the surface of the alumina, provide more adsorption sites for sodium, and increase the adsorption amount of sodium.

[0033] (2) In the sodium capturer of the present invention, an alumina - molecular sieve precursor is first prepared, and then inorganic acid is impregnated, which can effectively increase the acid content on the surface of the sodium capturer and improve the adsorption and capture amount of sodium.

[0034] (3) The sodium capturer of the present invention mainly adsorbs sodium through acid - base reaction. After being saturated with adsorption, the sodium in the adsorbent is removed by washing with ammonium salt water, and then inorganic acid is impregnated, so that the sodium capturer can be regenerated and recycled. The method is simple and the cost is reduced.

[0035] Other features and advantages of the present invention will be described in detail in the following specific implementation section. Specific Implementation Modes

[0036] The following non - restrictive examples can enable those of ordinary skill in the art to understand the present invention more comprehensively, but do not limit the present invention in any way.

[0037] In the present invention, the weight contents of the molecular sieve and alumina are analyzed by XRF (X - ray fluorescence spectrometry). Among them, the weight content of the molecular sieve is determined by measuring the silicon element content and then converted into the weight of the molecular sieve. The XRF test conditions are as follows: using the ZSX fluorescence spectrometer of Rigaku Corporation of Japan, with an output voltage of 20 - 60 KV and an output current of 2 - 150 Ma. After pressing the sample into a tablet, it is placed in the sample cell for testing.

[0038] The present invention uses N 2 - adsorption / desorption to analyze the specific surface area of the sample. The N 2 - adsorption / desorption test conditions are as follows: The catalyst is loaded into the sample tube, and the ASAP 2420 nitrogen physical adsorption instrument of Micromeritics Company of the United States is used to perform N 2 adsorption and desorption tests at a temperature of 77 K.

[0039] The present invention uses NH 3 - TPD (temperature - programmed desorption of ammonia) to analyze the acid content in the sodium capturer. The NH3 -TPD test conditions: Using the Auto Chem 2920 chemisorption instrument from Micromeritics, the catalyst was loaded into the sample tube, ammonia was adsorbed at 110 °C, then cooled to 50 °C, and the temperature was programmed to 500 °C in a helium atmosphere to measure the desorption amount of NH 3 .

[0040] The inorganic acid content in the prepared sodium trap was calculated from the weight difference before and after the introduction of inorganic acid during the preparation process.

[0041] The sodium oxide content in the sodium trap after the reaction was determined by X-ray fluorescence spectrometry (XRF). The XRF test conditions were as follows: Using the ZSX fluorescence spectrometer from Rigaku Corporation, Japan, with an output voltage of 20 - 60 KV and an output current of 2 - 150 Ma. After pressing the sample into a tablet, it was placed in the sample cell for testing.

[0042] The specific surface area of the alumina powder used in the following examples and comparative examples was 383 m 2 / g, and the pore volume was 0.86 cm 3 / g.

[0043] Example 1

[0044] (1) Sodium hydroxide, silica sol, sodium aluminate, and ethylenediamine were added to deionized water, and the molar ratio of each component was n(SiO 2 ):n(Al 2 O 3 ):n(Na 2 O):n(ethylenediamine):n(H 2 O) = 13:2:6:3:170. It was stirred until a homogeneous sol was formed, which was the precursor of Y zeolite. Then it was mixed with alumina powder, and then hydrothermally treated at 150 °C, 1.0 MPa, and pH = 8.0 for 10 h; then filtered, washed three times with deionized water, dried at 100 °C for 3 h, and calcined at 500 °C for 3 h to obtain a mixed powder.

[0045] (2) The mixed powder prepared in step (1) was mixed evenly with carboxymethyl cellulose, nitric acid, and deionized water (the weight ratio of each component was 100:3:1.5:80), then extruded into pellets, dried at 120 °C for 4 hours, and calcined at 500 °C for 4 hours to obtain the sodium trap precursor.

[0046] (3) An equal volume of nitric acid aqueous solution was impregnated into the sodium trap precursor prepared in step (2), and then dried at 90 °C for 3 hours to obtain the sodium trap CN-1.

[0047] The weight percentages of each component in the catalyst CN-1 were: alumina 85.7%, Y zeolite 10.1%, and nitric acid 4.2%.

[0048] Example 2

[0049] (1) Sodium hydroxide, silica sol, sodium aluminate and ethylenediamine were added to deionized water, and the molar ratio of each component was n(SiO 2 ):n(Al 2 O 3 ):n(Na 2 O):n(ethylenediamine):n(H 2 O) = 13:2:6:3:170. It was stirred until a homogeneous sol was formed, which was the precursor of Y zeolite. Then it was mixed with alumina powder, and then hydrothermally treated at 180 °C, 1.0 MPa and pH = 8.5 for 10 h. Then it was filtered, washed three times with deionized water, dried at 100 °C for 3 h, and calcined at 550 °C for 3 h to obtain a mixed powder.

[0050] (2) The mixed powder prepared in step (1) was mixed evenly with carboxymethyl cellulose, nitric acid and deionized water (the weight ratio of each component was 100:3:1.5:80), then extruded into pellets, dried at 120 °C for 4 hours, and calcined at 500 °C for 4 hours to obtain the sodium capture agent precursor.

[0051] (3) An equal volume of phosphoric acid aqueous solution was impregnated into the sodium capture agent precursor prepared in step (2), and then dried at 90 °C for 3 hours to obtain the sodium capture agent CN-2.

[0052] The weight percentages of each component in the catalyst CN-2 were: alumina 90.1%, Y zeolite 4.9%, and phosphoric acid 5.0%.

[0053] Example 3

[0054] (1) Sodium hydroxide, silica sol, sodium aluminate and ethylenediamine were added to deionized water, and the molar ratio of each component was n(SiO 2 ):n(Al 2 O 3 ):n(Na 2 O):n(ethylenediamine):n(H 2 O) = 13:2:6:3:170. It was stirred until a homogeneous sol was formed, which was the precursor of Y zeolite. Then it was mixed with alumina powder, and then hydrothermally treated at 200 °C, 0.5 MPa and pH = 8.5 for 10 h. Then it was filtered, washed three times with deionized water, dried at 100 °C for 3 h, and calcined at 600 °C for 3 h to obtain a mixed powder.

[0055] (2) Mix the mixed powder prepared in step (1) with sesbania powder, nitric acid, and deionized water (weight ratio of each component is 100:3:1.5:80) evenly, then extrude into strips, dry at 120 °C for 4 hours, and calcine at 550 °C for 4 hours to obtain the sodium capture agent precursor.

[0056] (3) Impregnate the sodium capture agent precursor prepared in step (2) with sulfuric acid aqueous solution in equal volume, and then dry at 80 °C for 3 hours to obtain the sodium capture agent CN-3.

[0057] The weight percentages of each component in the catalyst CN-3 are: alumina is 85.9%, Y zeolite is 8.0%, and sulfuric acid is 6.1%.

[0058] Example 4

[0059] (1) Add sodium hydroxide, silica sol, sodium aluminate, and n-butylamine to deionized water, where the molar ratio of each component is n(SiO 2 ):n(Al 2 O 3 ):n(Na 2 O):n(n-butylamine):n(H 2 O)=22:1:7:6:200, stir to form a homogeneous sol, which is the precursor of ZSM-5 molecular sieve, then mix with alumina powder, and then hydrothermally treat at 150 °C, 0.5 MPa, pH = 8.0 for 12 h; then filter, wash three times with deionized water, dry at 100 °C for 3 h, and calcine at 500 °C for 3 h to obtain the mixed powder.

[0060] (2) Mix the mixed powder prepared in step (1) with sesbania powder, nitric acid, and deionized water (weight ratio of each component is 100:3:1.5:80) evenly, then extrude into strips, dry at 120 °C for 4 hours, and calcine at 500 °C for 4 hours to obtain the sodium capture agent precursor.

[0061] (3) Impregnate the sodium capture agent precursor prepared in step (2) with phosphoric acid aqueous solution in equal volume, and then dry at 80 °C for 3 hours to obtain the sodium capture agent CN-4.

[0062] The weight percentages of each component in the catalyst CN-4 are: alumina is 86.0%, ZSM-5 molecular sieve is 8.0%, and phosphoric acid is 6.0%.

[0063] Example 5

[0064] (1) Dissolve sodium aluminate and sodium hydroxide in deionized water, then add tetraethylammonium bromide, stir vigorously, and slowly dropwise add silica sol, and age for 3 h, where the molar ratio of each component is n(SiO 2 ):n(Al 2 O3 ): n(Na 2 O): n(tetraethylammonium bromide): n(H 2 O) = 22:1:6:5:230 to form a precursor of β-type zeolite, and then mix it with alumina powder, and then hydrothermally treat it at 170 °C, 0.5 MPa, and pH = 8.5 for 20 h; then filter, wash three times with deionized water, dry at 100 °C for 3 h, and calcine at 600 °C for 3 h to obtain a mixed powder.

[0065] (2) Mix the mixed powder prepared in step (1) with sesbania powder, nitric acid, and deionized water (the weight ratio of each component is 100:3:1.5:80) evenly, then extrude it into pellets, dry at 120 °C for 4 hours, and calcine at 550 °C for 4 hours to obtain a sodium trap precursor.

[0066] (3) Impregnate the sodium trap precursor prepared in step (2) with an equal volume of phosphoric acid aqueous solution, and then dry at 80 °C for 3 hours to obtain a sodium trap CN-5.

[0067] The weight percentages of each component in the catalyst CN-5 are: 72.8% for alumina, 14.1% for β-zeolite, and 13.1% for phosphoric acid.

[0068] Example 6

[0069] (1) Mix cetyltrimethylammonium bromide with sodium hydroxide, then add it to deionized water. After stirring, add tetraethyl orthosilicate dropwise to the mixed solution. After stirring for 30 min, the molar ratio of each component is n(SiO 2 ): n(Na 2 O): n(cetyltrimethylammonium bromide): n(H 2 O) = 10:2:2:200 to form a precursor of MCM-41 zeolite, and then mix it with alumina powder, and then hydrothermally treat it at 180 °C, 1.0 MPa, and pH = 8.5 for 20 h; then filter, wash three times with deionized water, dry at 100 °C for 3 h, and calcine at 600 °C for 3 h to obtain a mixed powder.

[0070] (2) Mix the mixed powder prepared in step (1) with sesbania powder, nitric acid, and deionized water (the weight ratio of each component is 100:3:1.5:80) evenly, then extrude it into pellets, dry at 120 °C for 4 hours, and calcine at 650 °C for 4 hours to obtain a sodium trap precursor.

[0071] (3) Impregnate the sodium trap precursor prepared in step (2) with an equal volume of phosphoric acid aqueous solution, and then dry at 80 °C for 3 hours to obtain a sodium trap CN-6.

[0072] The weight percentages of the components in catalyst CN-6 are as follows: alumina is 83.5%, MCM-41 molecular sieve is 8.3%, and phosphoric acid is 8.2%.

[0073] Example 7

[0074] (1) First, form the alumina powder: Take the same alumina powder as in Example 1, add carmellose powder, nitric acid, and deionized water (the weight ratio of each component is 100:3:3:80), mix evenly, then extrude into strips, dry at 120°C for 4 hours, and calcine at 600°C for 4 hours to obtain the alumina support.

[0075] (2) Add sodium hydroxide, silica sol, sodium aluminate, and n-butylamine to deionized water, where the molar ratio of each component is n(SiO 2 ):n(Al 2 O 3 ):n(Na 2 O):n(n-butylamine):n(H 2 O) = 22:1:7:6:200, stir to form a homogeneous sol, which is the precursor of ZSM-5 molecular sieve, then mix it with the alumina support prepared in step (1), and then hydrothermally treat it at 160°C, 0.5 MPa, and pH = 8.0 for 12 h; then filter, wash three times with deionized water, dry at 100°C for 3 h, and calcine at 550°C for 3 h to obtain the sodium trap precursor.

[0076] (3) Impregnate the sodium trap precursor prepared in step (2) with an equal volume of phosphoric acid aqueous solution, and then dry at 80°C for 3 hours to obtain the sodium trap CN-7.

[0077] The weight percentages of the components in catalyst CN-7 are as follows: alumina is 85.3%, ZSM-5 molecular sieve is 8.2%, and phosphoric acid is 6.5%.

[0078] Example 8

[0079] (1) First, form the alumina powder: Take the same alumina powder as in Example 1, add carmellose powder, nitric acid, and deionized water (the weight ratio of each component is 100:3:3:80), mix evenly, then extrude into strips, dry at 120°C for 4 hours, and calcine at 650°C for 4 hours to obtain the alumina support.

[0080] (2) Add sodium hydroxide, silica sol, sodium aluminate, and ethylenediamine to deionized water, where the molar ratio of each component is n(SiO 2 ):n(Al 2 O 3 ):n(Na 2 O):n(ethylenediamine):n(H 2O) = 13:2:6:3:170, stir until a homogeneous sol is formed, which is the precursor of Y zeolite, and then mix it with the alumina support prepared in step (1). Then, hydrothermally treat it at 200 °C, 0.5 MPa, and pH = 8.5 for 10 h; then filter, wash three times with deionized water, dry at 100 °C for 3 h, and calcine at 600 °C for 3 h to obtain the sodium capture agent precursor.

[0081] (3) Impregnate the sodium capture agent precursor prepared in step (2) with an equal volume of phosphoric acid aqueous solution, and then dry at 80 °C for 3 hours to obtain the sodium capture agent CN-8.

[0082] The weight percentages of each component in the catalyst CN-8 are: 85.4% for alumina, 9.1% for Y zeolite, and 5.5% for phosphoric acid.

[0083] Comparative Example 1

[0084] (1) Mix alumina powder (with the same weight as the mixed powder in step (2) of Example 4) with carboxymethylcellulose powder, nitric acid, and deionized water (the weight ratio of each component is 100:3:1.5:80) evenly, then extrude into strips, dry at 120 °C for 4 hours, and calcine at 550 °C for 4 hours to obtain the sodium capture agent precursor.

[0085] (2) Impregnate the sodium capture agent precursor prepared in step (1) with an equal volume of phosphoric acid aqueous solution (operating parameters are the same as in Example 4), and then dry at 80 °C for 3 hours to obtain the contrast agent DC-1.

[0086] The weight percentages of each component in DC-1 are: 93.8% for alumina and 6.2% for phosphoric acid.

[0087] Comparative Example 2

[0088] Except for not performing step (3), other steps are the same as in Example 4 to obtain the contrast agent DC-2.

[0089] The weight percentages of each component in DC-2 are: 91.5% for alumina and 8.5% for ZSM-5 zeolite.

[0090] Comparative Example 3

[0091] Mix alumina powder with carboxymethylcellulose powder, nitric acid, and deionized water (the weight ratio of each component is 100:3:1.5:80) evenly, then extrude into strips, dry at 120 °C for 4 hours, and calcine at 550 °C for 4 hours to obtain the contrast agent DC-3.

[0092] The weight percentages of each component in DC-3 are: 100% for alumina.

[0093] Comparative Example 4

[0094] (1) Alumina powder and ZSM-5 molecular sieve were directly mixed in a weight ratio of 91.5:8.5 to obtain a mixed powder. The mixed powder was mixed evenly with carboxymethyl cellulose, nitric acid, and deionized water (the weight ratio of each component was 100:3:1.5:80), and then extruded into pellets. After drying at 120°C for 4 hours and calcining at 550°C for 4 hours, a sodium trap precursor was obtained;

[0095] (2) An equal volume of phosphoric acid aqueous solution was impregnated into the sodium trap precursor (the operating parameters were the same as in Example 4), and then dried at 80°C for 3 hours to obtain Comparative Example DC-4.

[0096] The weight percentages of each component in DC-4 were: alumina 86.0%, ZSM-5 molecular sieve 8.0%, and phosphoric acid 6.0%.

[0097] The acid content and specific surface area of the sodium trap agents prepared in the above examples and comparative examples were also measured, and the results are listed in Table 1.

[0098] Table 1

[0099] Catalyst Number Acid Content, mmol / g <![CDATA[Specific surface area, m 2 / g]]> CN-1 0.86 318.5 CN-2 0.76 274.5 CN-3 0.81 292.3 CN-4 0.79 292.3 CN-5 0.92 342.0 CN-6 0.76 271.7 CN-7 0.65 238.6 CN-8 0.69 246.9 DC-1 0.42 214.2 DC-2 0.61 268.0 DC-3 0.29 223.5 DC-4 0.54 232.3

[0100] Example 9

[0101] This example illustrates the sodium capture activity of the sodium trap agent provided by the present invention for naphtha.

[0102] The feedstock oil was naphtha provided by a refinery of Sinopec, with a sodium content of 174 μg / g and an unknown sodium source. If the oil product with a sodium content as low as 174 μg / g was treated by the electro - desalting method for crude oil, the cost would be very high. However, this part of sodium would poison the main hydrogenation catalyst, resulting in great economic losses. Therefore, in front of the main hydrogenation catalyst, the sodium trap agent of the present invention was loaded to remove sodium from the oil product. The sodium capture capabilities of sodium trap agents CN-1 to CN-8 and comparative examples DC-1 to DC-4 were evaluated using a 200 mL fixed - bed hydrogenation device. The evaluation reaction conditions were: operating pressure 3.0 MPa, reaction temperature 320°C, hydrogen / oil volume ratio 200:1, and volume space velocity 2.0 h -1 . During the reaction process, at about 100 h - 150 h, it was successively found that the sodium trap agents of DC1 - DC4 lost activity earlier and reached saturation, and the sodium content in the oil product no longer decreased. After running for 500 h, all sodium trap agents were saturated. The sodium trap agents were unloaded and then calcined at 500°C for 3 h, and the sodium content in the sodium trap agent was analyzed by XRF, which was the sodium capacity of the sodium trap agent. The evaluation results are shown in Table 2.

[0103] Table 2.

[0104] Catalyst Number <![CDATA[Sodium capacity (calculated as Na 2 O), %]]> CN-1 15.33 CN-2 13.55 CN-3 14.44 CN-4 14.08 CN-5 16.40 CN-6 13.55 CN-7 11.59 CN-8 12.30 DC-1 3.15 DC-2 8.21 DC-3 2.14 DC-4 4.23

[0105] As can be seen from Table 2, the sodium capture agent of the present invention has a higher sodium capacity.

[0106] Example 10

[0107] The regeneration of the sodium capture agent was carried out:

[0108] The CN-4 sodium capture agent after operation in Example 9 was mixed with a 0.8 g / mL ammonium nitrate solution and stirred for 8 hours. Then, after filtering the catalyst, it was dried at 120 °C for 6 hours. Subsequently, an equal-volume impregnation with a phosphoric acid aqueous solution was carried out (the operation parameters were the same as in Example 4) to obtain the regenerated sodium capture agent ZCN-4.

[0109] Comparative Example 5

[0110] For comparison with Example 10, without using ammonium salt solution impregnation, the regeneration of the sodium capture agent was carried out:

[0111] The CN-4 sodium capture agent after operation in Example 9 was mixed with deionized water and stirred for 8 hours. Then, after filtering the catalyst, it was dried at 120 °C for 6 hours. Subsequently, an equal-volume impregnation with a phosphoric acid aqueous solution was carried out (the operation parameters were the same as in Example 4) to obtain the regenerated sodium capture agent ZCN-5.

[0112] Example 11

[0113] The regenerated ZCN-4 and ZCN-5 sodium capture agents were evaluated for performance under the evaluation conditions of Example 9 to obtain the results of the sodium capacity of the sodium capture agents.

[0114] Table 3.

[0115] Catalyst Number <![CDATA[Sodium capacity (calculated as Na 2 O), %]]> ZCN-4 13.65 ZCN-5 3.83

[0116] As can be seen from Table 3, the regeneration method provided by the present invention can effectively restore the sodium capture ability of the catalyst.

Claims

1. A sodium capturer, comprising alumina, molecular sieve and inorganic acid, wherein the inorganic acid is selected from at least one of phosphoric acid, nitric acid, sulfuric acid and hydrochloric acid; the molecular sieve is crystallized on the alumina.

2. The sodium capturer according to claim 1, characterized in that based on the total weight of the sodium capturer, the weight percentage of the alumina is 50-95%, the weight percentage of the molecular sieve is 3-30 wt%, and the weight percentage of the inorganic acid is 4-20%.

3. The sodium capturer according to claim 1, characterized in that the total acid amount of the sodium capturer is 0.3-1.1 mmol / g.

4. The sodium capturer according to claim 1, characterized in that the molecular sieve is selected from at least one of Y-type molecular sieve, β-type molecular sieve and ZSM-5 molecular sieve.

5. A preparation method of a sodium capturer, comprising the following steps: (1) Mix alumina powder or shaped alumina with a precursor of the molecular sieve, carry out hydrothermal treatment, and after washing, drying and calcination, obtain a sodium capturer precursor; (2) Introduce inorganic acid into the sodium capturer precursor, and then carry out drying to obtain the sodium capturer.

6. The preparation method according to claim 5, characterized in that the precursor of the molecular sieve in step (1) is a gel formed by mixing a silicon source and / or an aluminum source, a precipitant, a template agent and water, and the molecular sieve is formed by a precipitation method or a sol-gel method.

7. The preparation method according to claim 6, characterized in that the silicon source is selected from one or more of sodium silicate, tetraethyl orthosilicate, silica sol and chromatographic silica gel; the aluminum source is selected from one or more of sodium aluminate, aluminum hydroxide and pseudo-boehmite; the precipitant is selected from at least one of sodium hydroxide, ammonia water and potassium hydroxide; the template agent is selected from one or more of cetyltrimethylammonium bromide, ethylenediamine, n-butylamine, tetrapropylammonium bromide, ethanol, tetraethylammonium hydroxide, tetraethylammonium bromide, triethylamine, di-n-propylamine, diisopropylamine and methylcellulose.

8. The preparation method according to claim 5, characterized in that the hydrothermal treatment conditions in step (1) are: temperature is 90-200 °C, pressure is 0.1-2.0 MPa, pH is 7.5-9.0, and time is 5-48 hours.

9. The preparation method according to claim 5, characterized in that the drying temperature in step (1) is 70-150 °C, the drying time is 4-16 hours; the calcination temperature is 400-800 °C, and the calcination time is 2-5 hours.

10. The preparation method according to claim 5, characterized in that the method for introducing inorganic acid in step (2) is an impregnation method.

11. The preparation method according to claim 5, characterized in that the drying temperature in step (2) is 80-120 °C, and the drying time is 3-8 hours.

12. The preparation method according to claim 5, characterized in that when the raw material used is alumina powder, it further includes the steps of mixing and extruding it with a peptizing agent, an extrusion aid and water after introducing the molecular sieve, and then carrying out drying and calcination.

13. The preparation method according to claim 12, characterized in that, the extrusion aid is selected from at least one of starch, polyethylene glycol and sesbania powder; calculated based on alumina, the addition amount of the extrusion aid is 2-8 wt% of alumina;; the peptizing agent is selected from at least one of nitric acid, phosphoric acid and acetic acid; calculated based on alumina, the addition amount of the peptizing agent is 1-8 wt% of alumina; the addition amount of water is 50-150 wt% of alumina.

14. The preparation method according to claim 5, characterized in that, The specific surface area of ​​the alumina powder is 300-500m 2 / g, pore volume is 0.9-1.4cm 3 / g.

15. A method for removing sodium from oil products, comprising contacting and reacting the oil products with the sodium scavenger according to claim 1 or the sodium scavenger prepared by the preparation method according to claim 5.

16. The method according to claim 15, characterized in that, The reaction conditions for oil de-sodium are as follows: the reaction temperature is 200 - 400 °C, the hydrogen partial pressure is 2.0 - 10 Mpa, and the volume space velocity is 0.5 - 6.0 h -1 .

17. A regeneration method for the sodium scavenger according to claim 1 or the sodium scavenger prepared by the preparation method according to claim 5, comprising the following steps: (1) Washing the sodium scavenger saturated with adsorption in an aqueous solution containing ammonium salt, and obtaining a regenerant precursor after drying; (2) Introducing inorganic acid into the regenerant precursor in step (1), and obtaining a regenerant after drying.

18. The regeneration method according to claim 17, characterized in that, the ammonium salt in step (1) is selected from one or more of ammonium nitrate, ammonium sulfate and ammonium chloride; calculated based on the mass of the ammonium salt, the concentration of the ammonium salt in the aqueous solution is 0.2-1.2 g / mL, and the washing time is 4-10 h.

19. The regeneration method according to claim 17, characterized in that, the drying conditions in step (1) are: the drying temperature is 90-150 °C, and the drying time is 3-8 h.

20. The regeneration method according to claim 17, characterized in that, in step (2), the inorganic acid is introduced by an impregnation method.